Additional notes from Raymond / info -at- arcadecomponents.com :

As a note, the Jr Manufacturing Diagnostics outputs to the serial port but the information isn’t included in that file.

It requires a null modem connection using RTS/CTS flow control and settings of 9600, 8 bits, No parity, and 2 stop bits.

If using Tera Term, you must use a macro of “setdebug 2” to enable the mode for it to show the hex value of characters received.

This will show you the error codes generated by the BIOS self-test routines.